Crossfire Configurations

[nate39]

I haven't considered crossfire until the 3800 series came out. I see there are three different AMD boards, the 770, 790x and 790fx. I realize that the cheaper chipsets have slower second gpu slots. From 16x to 8x to 4x.

Is there a simple way to know what real difference in speed there would be from one chipset in crossfire to another? And if the first slot had a 3870 and the second has a 3850 how much slower would it be than if you had 2x3870?

Thanks, I can't find a detailed explanation so all I know to do is ask.

[xMrBunglex]

i'm running an older 975X chipset motherboard, where both PCI-E lanes run at 8x speed in CF mode. i don't think there is any real performance hit compared to dual 16x lanes. since the 790X chipset uses PCI-E 2.0 (double the bandwidth), you shouldn't have any bottlenecking at all due to the 8x lane. i personally believe 790X gives the most performance per dollar spent. i don't think the extra bandwidth from 790FX can be used with today's video cards.

[nate39]

thanks, the 790X is much more in my budget and as long as the crossfire is good, it is plenty for what I want.